Belt-tightening appliance for elevating-graders.



No. 844,387. PATENTED FEB. 19, 1907.

V T. R; McKNIGHT. BELT TIGHTENING APPLIANCE FOR ELEVATING GRADERS.

APPLICATION FILED DEC. 29, 1905.

3 SHEETS-SHEET 1.

THE rvomzm FEYERS ca, WASHJNGYGN. u. c

UNITED STATES THOMAS R. MoKNIGHT, OF AURORA,

PATENT OFFICE.

ILLINOIS, ASSIGNOR TO WESTERN TION OF ILLINOIS.

BELT-TIGHTENING APPLIANCE FOR ELEVATING-GRADE RS.

Specification of Letters Patent.

Patented Feb. 19, 1907.

Application filed December 29, 1905. Serial No. 293,779.

To all w/wm, it may concern: 1

Be it known that I, THOMAS R. MCKNIGHT, i a citizen of the UnitedStates, residing at Aurora, 'in the county of Kane and State of 5Illinois, have invented certain new and useful Improvements inBelt-Tightening Appliances for ElevatingGraders, of which the followingis a specification, reference being had to the accompanying drawings.

My invention relates to elevating-graders and other machinery employingbelt conveyers, and has for one of its objects to provide a new andimproved construction for maintaining the GOIlVGYGIEbGlt at the propertension, by which the weight of the material on the belt is utilized forthat purpose A further object is to provide hand-open ated mechanism inconnection with such automatic mechanism, so that the proper tension maybe secured under extreme cons ditions, as where a very short elevator isused and the weight of the load alone is not sufficient to give theproper tension or, on the other hand, where a very long elevator is usedand the weight is too great and causes too great tension.

I accomplish these objects as illustrated in the drawings and ashereinafter described.

What I claim as new is set forth in the claims.

In the accompanying drawings, Figure 1 is an end elevation illustratingsome of the parts of an elevating-grader to which my improvements havebeen applied. Fig. 2 is an enlarged detail illustrating the outer endportion of the elevator. Fig. 3 is a plan view of the parts shown inFig. 2. Fig. 4 is an end view of the outer end of the elevator, and Fig.5 is a cross-section on line 5 5 of Fig. 3.

Referrin to the drawings, Fig. 1 illustrates one form 0 anelevating-grader to which my improvements may be applied. It will beunderstood that such machines comprise a carriage which supports anelevator in the form of a belt conveyer arranged to receive dirt from aplowing device suitably disposed, suitable provision being made foroperating the conveyer by the progressive movement of the machine. Sucha machine is illustrated and described in Letters Patent No. 727,671,granted to me May 12,- 1903. As much of the mechanism by which stoodthat my improvements may be applied to machines of various types inwhich it is desirable to employ a belt conveyer or in whichtension-adjusting devices are desirable.

Referring now to the drawings, 6 indicates the carriage, which may be'afour-wheeled carriage of the usual type, and 7 indicates the elevator.In the form shown the elevator is composed of a number of sections,(marked, respectively, A, B, and O.) The sections B O are of the typeillustrated in the patent above referred to and are connected by ahinge-joint at 8, as shown in Fig. 1. The outer section A contains theprincipal part of the mechanism by which the tension on the belt isregulated.

9 indicatesthe conveyer-belt, which, as indicated by dotted lines inFig. 1, runs over end pulleys 10 11 and intermediate pulleys 12. Thepulleys 11 12 are ordinary pulleys mounted in bearings of any suitabletype provided in the various sections of the elevator. The pulley 10,however, is mounted so as to be adjustable toward and from the pulley11, and thereby vary the tension upon the belt. Said pulley is mountedupon a shaft 13, which is mounted in suitable bearings 14, which will behereinafter described. It carries a sprocket-wheel 15, by which it isconnected with a suitable drive-shaft mounted on the carriage and drivenfrom one of the wheels or wheel-axles, so that as the machine progressesthe belt is caused to travel. As best shown in Figs. 2 and 4, thebearings 14 are carried at the outer end portions of slides 16, whichare preferably T-shaped in cross-section, as shown in Fig. 4. Saidslides are fitted to slide longitudinally .on the elevator in bearings17, carriedby the frame A, as shown in Fig. 5. By this construction thepulley 10 may be moved inward and outward, the slides movinglongitudinally in the bearings 17. Preferably the slides 16 carry thelongitudinally-disposed rollers 18, which are usually provided at theouter end of the elevator-frame.

As best shown in Fig. 3, the slides 16 at the opposite sides of themachine are connected by cross-bars 19 20 and diagonal braces 21 22,besides being connected by the shaft 13, as already described, so thatsaid slides, together with the cross-bars and braces, form a slidingframe which is adapted to move longitudinally of the elevator. Atopposite sides of said frame, are provided racks 23, extendinglongitudinally of the frame, as shown in Fig. 3. 24 indicates a shaftmounted in the frame A in suit able bearings and extending transverselythereof, as shown in Fig. 3. Said'shaft carries at its end portionspinions 25, which mesh with the racks 23, so that by rotating said shaft24 the sliding frame may be moved longitudinally of the elevator ineither direction.

As shown in Fig.3, the ends of the shaft 24 project beyond the sides ofthe elevator and carry pulleys 26, which are loose onthe shaft. At oneend' portion is a pulley or sheave 27, which is fast on the shaft, sothat by rotating said pulley the shaft may be rotated to adjust theposition of the sliding frame. 23 indicates chains or other flexibleconnections which pass around the pulleys 26 and are connec'ied to'theinner portion of the sliding frame, preferably by hooks 29. (Shown inFigs. 2 and 3.) The upper ends of the chains are connected to the upperend portions of sirui's 30, which are connected by chains 31 withsuitable hoisting mechanism 32. (Shown in Fig. 1..) By aci uating thehoisting mechanism the inclination of the struts 30 may be varied. Thehoisting mechanism is of course arranged so that it may be lockedagainst rotation, thereby holding the struts 30 in any desired positionof adjustment. By the construction above described the weight of theelevator-frame, together with the load carried by the elevator, acts toforce the extensible or sliding frame outward, and thereby put the beltunder tension, this action being automatic. In order to place theregulation of the tension under the control of the operator, however, Iprovide a tension-lever 33, fulcrumed at 34 upon the frame of themachine and connected by a chain 35 with the pulley 27, as shown inFigs. 1 and 2, said chain passing 'over one or more suitableguide-rollers 36, as shown in Fig. 1. The lever 33 is provided with theusual pawl 37 and segmental rack 38 or other suitable locking mechanism,by which it may be locked in different positions of adjustment. Thearrangement is such that by operating the lever 33 the pulley 27, andconsequently the shaft 24, may be rotated in the direction indicated bythe arrow in Figs. 1 and 2, thereby moving the extensible frame andpulley 10 inward l l l the lever 33 at any desired point the extent towhich the tension is increased automatioally by the load may be limited.

Where the load is insuflicient to secure the requisite tension on thebelt, the sliding frame may be forced outward positively by theoperating-lever 33 after first slipping the chain 35 over the top of thesheave 27. Actuation of the lever 33 therefore acts to move the slidingframe outward instead of inward. In this manner I avoid the necessity ofproviding a separate lever and sheave for effecting the outward movementof the sliding frame.

By the construction above described provision is made by which thetension upon the conveyer-belt is automatically regulated to, a certainextent by the weight of the elevatorframe and load without interferingwith the separate adjustment thereof by the operator when desirable, sothat the tension of the belt at all. times may be accurately controlled.

The shaft 24 and pinions 25, in addition to providing for moving thesliding frame inward and outward, serve to equalize the strain on thesliding frame, so that one side of the frame may not be by undue strainmoved outwardly ahead of the other side, thereby causing the belt to runtoward one side or the other, due to an uneven load on the conveyor. Therunning of the belt true to center is insured by means of the shaftdescribed In the construction shown the outer frame A is made in theform of a detachable exten sion applied to frame B and secured theretoby side plates 39 40. By this construction the sliding frame may bereadily applied to or removed from the elevator-frame but so far as thegeneric features of my invention are concerned they are not limited toso constructing the frame A.

41 indicates a guide-roller for the sprocketchain, which is mounted. ina suitable bracket 42, carried by the frame A.

43 indicates the side boards of the elevator-frame.

It will be understood that my invention is not restricted to thespecific features of the construction illustrated and described exceptin. so far as they are specifically claimed, but includes genericallythe subject-matter of the broader claims.

That which I claim as my invention, and desire to secure by LettersPatent, is

1.. The oombinationof an elevator-frame, an extensible frame cooperatingtherewith, a conveyor-belt carried by said elevator-frame and saidextensible frame, and means operated by the load for positively forcingsaid extensible frame outward.

2. The combination of an elevator-frame, a conveyer-belt, and meanspositively actuaated by the weight of the load for automaticallyincreasing the tension of the conveyerbelt.

3. The combination of an elevator-frame, an extensible frame cooperatingtherewith, a conveyer-belt carried by said frames, and means positivelyactuated by the weight of the load for automatically increasing thetension on they conveyer-belt.

4. The combination of an elevator-frame, an extensible frame cooperatingtherewith, a conveyer-belt carried by said frames, means controlled bythe weight of the load for varying the tension on said belt, and meansfor limiting the tension applied to the belt.

5. The combination of a carriage, an elevator-frame, an extensibleframe, a conveyerbelt carried by said frames, a lever mounted on thecarriage, and means connected with said lever for moving said extensibleframe inwardly.

6'. The combination of a carriage, an elevator-frame, an extensibleframe, a conveyerbelt carried by said frames, a lever mounted on thecarriage, and means connected with said lever for moving said extensibleframe either inwardly or outwardly at pleasure.

7. The combination of a carriage, an elevator-frame, an extensible framecooperating therewith, a conveyer-belt carried by said frames, and meansmounted on the carriage connected with the opposite sides of saidextensible frame for moving it either inward or outward at pleasure.

8. The combination of a carriage, an elevator frame, a slidingextensible frame cooperating therewith, a conveyer-belt carried by saidframes, and means mounted on the carriage for moving said extensibleframe either inward or outward at pleasure to vary the tension on thebelt.

9. The combination of a carriage, an elevator-frame, a slidableextensible frame cooperating therewith, a conveyer-belt carried by saidframes, a shaft, pinions carried by said shaft at opposite sides of saidextensible frame, racks carried by said extensible frame and meshingwith said pinions, and means mounted on the carriage for rotating saidshaft in either direction.

10. The combination of a carriage, an elevator-frame, an extensibleframe cooperating therewith, a conveyer-belt carried by said frame, andmeans mounted on the carriage for applying power to the opposite sidesof said extensible frame for moving it either inward or outward atpleasure.

11. The combination of a carriage, an elevator-frame, an extensibleframe cooperating with said elevator-frame, a conveyer-belt carried bysaid frames, and means connected with the carriage and ositivelyactuated by the weight of the load 'or automatically varying the tensionapplied to the conveyer-belt.

12. The combination of a carriage, an elevator-frame, an extensibleframe cooperating with said elevator-frame, a conveyer belt carried bysaid frames, means connected with the carriage for automatically varyingthe tension applied to the conveyer-belt, and means mounted on thecarriage for positively adjusting the position of the extensible frame.

13. The combination of a carriage, an elevator-frame, an extensibleframe cooperating with said elevator-frame, a conveyer-b elt carried bysaid frames, pulleys carried by the elevator-frame, and flexibleconnections running over said pulleys and connected at one end with thecarriage and at the other end with the inner portions of said extensibleframe for automatically varying the tension upon the belt.

14. The combination of a carriage, an elevator-frame, an extensibleframe cooperatin therewith, a conveyer-belt carried by sai frames, ashaft carried by said elevator-frame, a sheave carried by saidshaft,.rack-and-pinion mechanism connecting said shaft with saidextensible frame, a lever mounted on the carriage, and a flexibleconnection connecting said lever with said sheave whereby by operatingsaid lever said shaft may be rotated to vary the tension on the belt.

15. The combination of a carriage, an elevator-frame, an extensibleframe cooperating therewith, a conveyer-b elt, sheaves carried by saidelevator-frame, a strut mounted on the carriage, and flexible meansrunning over said sheaves and strut, said flexible means being connectedwith the inner portion of said extensible frame and with the carriage.

16. The combination of acarriage, an elevator-frame, an extensible framecooperating with said elevator-frame, a conveyer-belt carried by saidframes, and means connected with the carriage for positively moving saidextensible frame in either direction to vary the tension of theconveyer-belt.

17. The combination of a carriage, an elevator having a conveyer-belt,and positivelyacting means connected with the carriage for eitherincreasing or reducing the tension of said conveyer-belt at pleasure.

18. The combination of a carriage, an elevato'rframe, an endlessconveyer,lever mechanism mounted on the carriage, and means positivelyactuated by said lever mechanism for reducing the tension of saidconveyer.

19. The combination of an elevator-frame, an endless conveyer, meanscontrolled by the weight of the load for automatically varying thetension of said conveyer, and adjustable means for limiting the extentto which the tension may be automatically increased.

20. The combination of an elevator-frame, an endless conveyer, meanspositively actuated by the weight of the load for automat- IIO icallyincreasing the tensionof said conveyer, and h andoperated means forvarying the tension: of the conveyor.

21:. The combination of an elevator-frame, an. extensible frame carriedby said. elevatorframe, a conveyer-beltcarried bysaid frames, one ofsaid framesbeing movableto vary the tensionupon said belt, and meanscontrolled by the Weight of the load for positively actuating' saidextensible frame to increase the tension on the conveyer-belt.

22. The combination of: an. elevator-frame, an extensible frame carriedby said elevatorframe, a conveyor-b elt carried by said frames, one ofvsaid'frames being. movable inward and outward tovary the tension uponsaid belt,

and means controlled by the Weight of the load for positively movingsaid extensible frame outward toincrease the tension on the conveyer-belt.

23. The combination of a carriage, an eleincreasethe tension on theconveyer-belt, a I

lever mounted on the carriage, and means connected With said lever-forpositively actuating said extensible frame to vary the tension ontheconveyer-belt.

THOMAS R.-MOKNIGH T. Witnesses:

G. E. BEOKWITH', M. T. B'ABB.

